Piston



Feb. 20, 1934.

' H; H. WAGNER PISTON File'd March 13 1931 27 gamut; Co.

2a H w 1171/ His ATTOR NEY-S.

UNITED STATES PATENT OFFICE PISTON Harold H. Wagner, Wausau, Wis., assignor of one-half to George A. Wagner, Wausau, Wis.

Application March 13, 1931. Serial No. 522,363 1 Claim. (c1. 309-14) This invention relates to certain novel improvements in piston, and has for its principal object the provision of an improved construction of this character which will be highly efilcient in use and economical in manufacture.

One of the objects of this invention is to provide an improvement over the piston disclosed in my U. S. Patent #1373329, date of August 26, 1930, in which patent a sleeve is provided that encircles the body of the piston throughout the length of the piston, with the rings disposed in grooves in the said sleeve. In the present invention, as will appear hereinafter, I provide a sleeve that extends over only part of the surface of the piston and the rings are disposed in grooves in the body of the piston and not in the sleeve, as is the case in the type of construction disclosed in the patent above referred to. This improvement provides for better compression while making it possible to make the sleeve of lighter construction.

It is another object of the invention to provide a piston which will eliminate the piston slap" of internal combustion engines, caused by loose pistons.

Another object of the invention is to provide a piston in which the sleeve forms the greater of the skirt of the piston and to provide a resilient sleeve which will expand and contract with the temperature of the cylinder.

An additional object of the invention is to provide an improved piston which will effectively prevent leakage past the piston and to prevent scoring and freezing" of the piston.

A further object of the invention is to eliminate danger of cylinder wall scoring by loosening of they wrist pin.

Other objects will appear hereinafter.

The invention consists in the novel combination and arrangement of parts to be hereinafter described and claimed.

The invention will be best understood by reference to the accompanying drawing showing the preferred form of construction, and in which:

' Fig. 1 is a view, partly in top plan and partly in section, on the line 1-1 in Fig. 2; 1

Fig. 2 is a side elevational view of a preferred form of construction of the invention;

Fig. 3 is a sectional view on the line 3-43 in 18. 1:

Fig. 4 is a' sectional view on the line 4-4 in F18. 3: and

Fig. 5 is a side elevational view of a modified form of construction of the invention.

Referring now to Figs. 1 to 4, wherein a preferred form of construction of the invention is illustrated, generally indicated at 10 is the main body portion of my improved piston which may be of any suitable material such, for example, as aluminum. Provided in the upper or ring portion of the body 10 of the piston is a plurality of concentric annular grooves 11 for the reception of suitable piston rings.

Below the ring grooves 11 a ring groove 12 is (15 provided in the body 10 and extending into the body 10 from this groove 12 is an annular recess or groove 13 so that an annular shoulder 14 is formed and this shoulder overlies the recess or groove 13.

My improved sleeve is indicated at 15 and includes an internal flange 16 that fits into an annular groove 17 formed in the body 10 of the piston. Above the internal flange 16, an inwardly extending flange 18 is provided on the sleeve 15 and at its inner end this flange 18 has formed integral therewith a rightangularly extending portion 19, so that the flange 18 and its portion 19 are substantially L-shaped in cross section, with the portion 19 disposed in the recess or groove 13 and against or under the shoulder 14. At its lower or inner end, the sleeve 15 has an internal flange 20 formed thereon which fits into a corresponding groove in the skirt portion of the piston body 10. In this manner the sleeve 15 is held rigid on the piston body 10 and up and down play ofthe sleeve on the body 10 is prevented. If desired, however, additional grooves 17 in the body 10 and cooperating internal flanges 16 on the sleeve 15 may be provided.

Indicated at 22 is a split in the sleeve 15, extending at an angle with respect to the longitudinal axis of the piston and sleeve so that the split 22 will not score thecylinderwall. When the sleeve 15 and piston body 10 are not in the cylinder, the sleeve will be expanded relatively wider than it appears in Fig. 2, in which the sleeve appears as if mounted in a cylinder. The sleeve 15 being of innately resilient material such, for example. as cast iron, will expand against the cylinder wall and thereby bring about close contact between the outer surface of the fieeve and the cylinder wall, to eliminate piston Indicated at 23 is a split in the body 10 of the piston, which prevents undue expansion of the piston body 10 and excessivev pressure on the sleeve 15. l

..,The wrist pin bosses on'thebody 10 are indicated at 24 and 25 and anoil groove 26 is formed in the sleeve 15 to help push oil up into the cylinder and to assist in proper lubrication.

In Fig. 5 the piston body 10' has the ring grooves 11' formed therein and below these grooves 11 are two (or more if desired) grooves 27 which are separated by an annular shoulder 28 formed on the body 10 and this shoulder 28 is disposed in a corresponding recess 29 in the sleeve 15. At the lower or inner end of sleeve 15' is an internal flange 20 that is disposed in the annular groove 21', and thus it will be seen that in mounting the sleeve 15' on the piston body 10, the recess 13 in the body 10 and the flange portion 19 on the sleeve are eliminated while their place is takenby the groove 29, ring 28, and internal sleeve flanges 16, similar to the flange 16.

Thus it will be seen that the piston rings employed with my present improvement are mounted directly on the body 10 of the piston while the ring fitting into groove 12 will abut shoulder 14 of the body 10 and flange portion 19. The present improvement provides for better compression and lighter sleeve construction than with the piston construction described in my above identified patent, and from the foregoing description of the present invention it will be seen that I have provided a piston construction which will eliminate or at least minimize piston slap, lost compression due to leakage past the piston, and freezing and scoring of the piston. The provision of sleeve 15, or 15, likewise prevents scoring due to the loosening of the wrist pins which cannot engage the cylinder wall due to the provision of the sleeve, while the arrangement of the split sleeve and split piston provides for expansion and contraction of both sleeve and piston body with engine temperatures.

While I have illustrated and described the preferred form of construction for carrying my invention into effect, this is capable of variations and modification without departing from the spirit of the invention. I,'therefore, do not wish to be limited to the precise details of construction set forth, but desire to avail myself 01 such variations and modifications as come within the scope of the appended claim.

Having thus described my invention, what I claim as new and desire to protect by Letters Patent is:

A piston comprising a main body having a series of ring-receiving grooves formed in the upper extent of its face, and having other grooves formed therein below said first-named grooves including a groove disposed near the bottom of said body, a sleeve extending over substantially less than the entire length of said body of the piston, internal flanges on said sleeve disposed in said other grooves, said body having an annular recess extending thereinto from, and opening outwardly into, the bottom of the lowest of said ring-receiving grooves, and a flange formed on the upper end of said sleeve, said flange portion consisting of two intersecting arms one shorter than the other and the shorter of said arms being disposed in said annular recess and adapted to be locked therein by a ring disposed in the lowest of said ring-receiving grooves, said lastnamed flange being substantially L-shaped in cross section, said cross section being considered as extended axially of said piston, and the radially outer surface of the shorter of said arms of said flange portion lying in the same plane with the outer surface of that portion of said lowest ring-receiving groove which lies above and radially outwardly from said recess, and the radially outer surface of said shorter arm cooperating 1m with the said outer surface of said lowest ringreceiving groove to form a straight sided face for the reception of a ring, said plane being considered as being passed axially through said piston.

HAROLD H. WAGNER. 

